We have requirement where based on Country User comes from Datasource should change corresponding to that country for example if User is accessing Site from China then Datasource should point towards China folder and if he is logging from UK it should point towards from UK folder
You can use personalization rule for your footer component.
There is a rule in GeoIP section:
where the country [compares to] [specific country]
If you're not using paid services, you may need to implement custom IP to country detection. But there are plenty of articles about GeoIP detection with free MaxMind databases, e.g:
Keep in mind that all the GeoIP databases are not perfect.
Remember also that you should define default datasource which will be used if you have no datasource for that particular country.
EDIT after OP's comment: If you're not using xDB, you can do the same just using session/cookie instead of saving this information in contact. Find country based on user IP using free MaxMind database (or other db), set this info in cookie/session, copy code of geoip country rule and change it to compare country from cookie/session instead of xdb.
EDIT after anothe OP's comment: In order to personalize a Sitecore component, you don't need to write any code: https://doc.sitecore.net/sitecore_experience_platform/digital_marketing/personalization/walkthrough_personalizing_components
You can personalize without xDB, see here: https://sitecore.stackexchange.com/a/4769/277